In recent years, fuel cell modules that house a fuel cell stack device in a housing container, the fuel cell stack device being constituted by a plurality of fuel cells arranged, and fuel cell devices that each house the fuel cell module in an external casing have been proposed as next generation energy sources. The fuel cells are a type of cell capable of generating power using a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (air) (e.g., Patent Literature 1).